A Cusum Based Fault Detection Technique For Comensated Line During Power Swing
Distance relays perform a key role in the protection of transmission lines, however it is susceptible to power
swing thus false operates. To avoid unintended trip operation during such conditions, usually power swing blocking function
is used as soon as the swing is detected in distance relays. Any Fault in the system at any moment of time, relay should
detect the fault and trip earliest. Even during power swing if a fault occurs relay is supposed to its defined work. The
detection of fault in series compensated line during power swing is further complex due to the transients produced by series
capacitor and the Metal Oxide Varistor (MOV) protecting it. This paper proposes negative sequence current based technique
for detection of all types of faults. Algorithm is tested forTwo source test system, series and shunt compensated IEEE 14 bus
test system. Faults: Unsymmetrical grounded, unsymmetrical unground, symmetrical faults and high resistance faults are
simulated through MiPower/ETA software to test the algorithm in Scilab. Performances of the developed algorithm have
been verified by using these simulated cases and from field data.
Keywords—Distance Protection, Power Swing, Fault Detection, Series Compensation, CUSUM.